public class Solution1663 {
    public String getSmallestString(int n, int k) {
        int t=26*n-26-k;
        if (t==-26){
            StringBuilder stringBuilder=new StringBuilder();
            for (int i = 0; i < n; i++) {
                stringBuilder.append('z');
            }
            return stringBuilder.toString();
        }
        for (int i=1;i<=26;i++){
            if ((t+i)%25==0){
                StringBuilder stringBuilder=new StringBuilder();
                for (int j=0;j<(t+i)/25;j++){
                    stringBuilder.append('a');
                }
                stringBuilder.append((char)('a'+i-1));
                while (stringBuilder.length()<n){
                    stringBuilder.append('z');
                }
                return stringBuilder.toString();
            }
        }
        return "";
    }

    public static void main(String[] args) {
        System.out.println(new Solution1663().getSmallestString(2,52));
    }
}
